WCE 2019: Buyer Beware: Evidence-Based Evaluation of Dietary Supplements for Nephrolithiasis

Abu Dhabi, United Arab Emirates (UroToday.com) Dr. Kevin Koo’s study is about dietary supplements for kidney stones and was borne out of a concern he and his colleagues saw in their clinics. Many urologists have been in situations where their patients who are current stone formers bring in various commercially-available and unregulated supplements. In the United States, supplements are not regulated as prescriptions but rather as food by the Food and Drug Administration. Dr. Koo’s group wished to better counsel patients on supplement use for stones.

Supplements come in a variety of shapes and forms. They claim to treat and prevent stones and stone symptoms. However, the evidence for them is unclear. The purpose of this study was to assess what level of scientific evidence, if any, there was to support commercial dietary supplements for urinary stone disease.

wce 2019 dietary supplements for urinary stone disease

Using sources that his patients would ordinarily go to for these supplements such as Amazon, Google, and the local health foods stores, Dr. Koo identified 27 different supplements that included 56 non-pharmalogic ingredients. When Dr. Koo and his colleagues assessed these 56 ingredients and tried to find evidence in the literature for their use, they found that 84% of these ingredients had no published studies for stone disease in humans or animals. Of the remaining 16% of ingredients that included any published studies, only 9% were supported by studies for use in urinary stone disease. Based on this, there was 18 products with conflicting, refuted, or absent evidence of benefits. Many patients, Dr. Koo believes, do not know this. When patients look at ingredients labels and see herbal and “natural” remedies, they may believe that there is an active use for them and that they have been studied by scientific means. This is simply not the case.

In conclusion, two-thirds of commercially available dietary supplements claiming to treat or prevent kidney stones contain ingredients with conflicting or no scientific evidence. Dr. Koo warns us that the absence of evidence for supplements does not mean there is an absence of harm. Patients should always be informed that because many of these ingredients have not been studied, there is a potential that they could be impairing their health.

Presented by: Kevin Koo, MD, MPH, Johns Hopkins University School of Medicine, Baltimore, Maryland